JP7155364B2 - Gas-liquid separator for fuel cells - Google Patents

Description

The present invention relates to a gas-liquid separator for fuel cells.

Japanese Patent Application Laid-Open No. 2007-87718 discloses a fuel cell fuel cell having a separation unit that separates water from an off-gas of a fuel cell, and a gas discharge unit that discharges the off-gas from which water is separated by the separation unit to the outside from the separation unit. A gas-liquid separator is disclosed.

However, the fuel cell gas-liquid separator disclosed in the above publication has the following problems.
When separated water is present on the side surface portion above the gas discharge portion of the inner surface of the separation portion, when the water flows downward under its own weight, it is carried away by the gas flow passing through the gas discharge portion, and the gas is discharged. There is a risk that it may leak out from the part. Therefore, there is room for improvement in improving the gas-liquid separation performance of the gas-liquid separator.

Japanese Patent Application Laid-Open No. 2007-87718

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas-liquid separator for a fuel cell that can improve the gas-liquid separation performance compared to the conventional one.

The present invention for achieving the above object is as follows.
(1) A gas-liquid separator for separating a liquid from a fuel cell off-gas,
a separation unit that separates a liquid from the off-gas;
an offgas introduction section that introduces the offgas into the separation section;
a gas discharge unit for discharging the off-gas, the liquid of which is separated by the separation unit, from the separation unit to the outside of the gas-liquid separator;
a liquid drain section provided below the separation section into which the liquid separated by the separation section flows and is discharged to the outside of the gas-liquid separator;
has
The separation section has a collision section provided at a position above the gas discharge section and at a position opposite to the offgas introduction section, where the offgas introduced from the offgas introduction section directly collides,
A head portion is provided at a position below the collision portion and above the gas discharge portion to prevent the liquid separated by the collision portion from flowing downward under its own weight and flowing into the gas discharge portion.
Gas-liquid separator for fuel cells.
(2) The gas-liquid separator for a fuel cell according to (1), wherein the head portion protrudes into the separating portion from the inner surface of the separating portion.
(3) A plurality of vertically extending grooves are provided in at least a portion of the inner surface of the separating portion excluding the portion above the gas discharging portion, (1) or (2). Gas-liquid separator for fuel cells as described.
(4) Among the grooves, the distance between the first groove provided closest to the gas discharge portion and the second groove provided next to the first groove is the distance between the other two adjacent grooves. The gas-liquid separator for a fuel cell according to (3), which is smaller than the interval.

According to the fuel cell gas-liquid separator (1), the following effects can be obtained.
Since the umbrella portion is provided, it is possible to prevent the liquid separated at the collision portion of the separation portion from flowing downward under its own weight and flowing into the gas discharge portion. Therefore, it is possible to suppress the liquid separated by the separation section from flowing into the gas discharge section, and to improve the gas-liquid separation performance of the gas-liquid separator, compared to the case where the umbrella section is not provided.

According to the fuel cell gas-liquid separator of (2) above, the following effects can be obtained.
Since the head portion protrudes into the separation portion from the inner surface of the separation portion, the head portion can be provided with a simple structure, which is advantageous in terms of cost.

According to the fuel cell gas-liquid separator of (3) above, the following effects can be obtained.
The liquid separated by the separating section flows along the groove. Therefore, the liquid adhering to the inner surface of the separating section can be efficiently guided to the liquid draining section as compared with the case where the groove is not provided. Therefore, it is possible to prevent the liquid separated by the separation section from re-scattering due to the gas flow and flowing into the gas discharge section.

According to the fuel cell gas-liquid separator of (4) above, the following effects can be obtained.
Since the interval between the first groove and the second groove is smaller than the interval between the other two adjacent grooves, the interval between the first groove and the second groove is the interval between the other two adjacent grooves. The first groove can be provided farther from the gas outlet than if it were the same as the spacing. Therefore, the liquid flowing along the first groove can be flowed away from the gas discharge portion, and the liquid flowing along the first groove can be prevented from flowing into the gas discharge portion.

1 is a schematic cross-sectional view of a gas-liquid separator for a fuel cell according to an embodiment of the present invention; FIG. 1 is an exploded perspective view of a gas-liquid separator for a fuel cell according to an embodiment of the present invention, viewed obliquely from above; FIG. 1 is an exploded perspective view of a gas-liquid separator for a fuel cell according to an embodiment of the present invention, viewed obliquely from below; FIG. 1 is a perspective view of only an upper member and a strainer in a gas-liquid separator for a fuel cell according to an embodiment of the present invention, viewed from below; FIG. FIG. 3 is a cross-sectional view showing only the upper member and the strainer in the fuel cell gas-liquid separator of the embodiment of the present invention; FIG. 6 is a partial enlarged cross-sectional view taken along line BB of FIG. 5; 1 is a system diagram of a fuel cell system provided with a gas-liquid separator for a fuel cell according to an embodiment of the present invention; FIG. 1 is a system diagram of a fuel cell system provided with a gas-liquid separator for a fuel cell according to an embodiment of the present invention, in which a humidifier is provided in an inlet-side oxidant gas pipe; FIG.

A fuel cell gas-liquid separator (hereinafter also simply referred to as a gas-liquid separator) 10 of an embodiment of the present invention will be described below with reference to the drawings. Note that UP in the figure indicates upward.

The gas-liquid separator 10 is mounted, for example, on a fuel cell vehicle. However, it may be installed in a vehicle other than an automobile. The fuel cell is, for example, a solid polymer electrolyte fuel cell.

A polymer electrolyte fuel cell consists of a laminate of a membrane-electrode assembly (MEA) and a separator. The membrane-electrode assembly includes an electrolyte membrane made of an ion-exchange membrane, an electrode (anode, fuel electrode) having a catalyst layer disposed on one side of the electrolyte membrane, and an electrode having a catalyst layer disposed on the other side of the electrolyte membrane. (cathode, air electrode). The separator has a fuel gas channel for supplying fuel gas (hydrogen) to the anode, and the cathode has an oxidizing gas channel for supplying oxidizing gas (oxygen, usually air). . A membrane-electrode assembly and a separator are laminated to form a cell, at least one cell forms a module, the modules are laminated to form a cell laminate, and a fastening member extending in the cell lamination direction outside the cell laminate (for example, tension plate), and fixed with bolts and nuts to form the stack 100 .

FIG. 7 schematically shows the gas system of the fuel cell (including fuel gas, oxidizing gas, gas supply system, gas discharge system, and gas circulation system).
Fuel gas is supplied from a fuel gas source 101 (for example, a high-pressure hydrogen tank) to the stack 100 through an inlet-side fuel gas pipe 102, is partially consumed and flows to an outlet-side fuel gas pipe 103, and is mostly fuel gas. The gas is circulated to the fuel gas pipe 102 on the inlet side via the gas circulation pipe 104 and the circulation pump 105, and the remainder is discharged to the atmosphere from the fuel gas pipe 103 on the outlet side.
Oxidant gas is taken in from the atmosphere by a compressor 106, supplied to the stack 100 through an inlet-side oxidant gas pipe 109 provided with an air cleaner 107 or the like, and partly consumed and flowed to an outlet-side oxidant gas pipe 110, Emitted to the atmosphere. As shown in FIG. 8, a humidifier 108 may be provided in the oxidizing gas pipe 109 on the inlet side.

The fuel gas pipe 103 on the delivery side constitutes an off-gas system for the fuel gas, and the oxidizing gas pipe 110 on the delivery side constitutes an off-gas system for the oxidizing gas.
Gas-liquid separators 10 are provided on the fuel gas side for the fuel gas pipe 103 on the delivery side and on the oxidant gas side for the oxidant gas pipe 110 on the delivery side. is separated from the fuel off-gas, and liquids (moisture, etc.) in the oxidant off-gas are separated from the oxidant off-gas.

The gas-liquid separator 10, as shown in FIG. An off-gas introduction part 14, a gas discharge part 16 for discharging the off-gas whose liquid has been separated by the separation part 12 from the separation part 12 to the outside of the gas-liquid separator 10, and a separation part 12 provided below the separation part 12 and a draining part 18 into which the liquid separated by the flow is discharged to the outside of the gas-liquid separator 10 .

The separation section 12 is provided in the upper portion of the gas-liquid separator 10 and separates the liquid from the off-gas introduced into the gas-liquid separator 10 from the off-gas introduction section 14 . A method of separating the liquid by the separation unit 12 is, for example, an inertial collision method. Therefore, the separation section 12 has a collision section 12a which is provided at a position opposite to the offgas introduction section 14 and with which the offgas introduced from the offgas introduction section 16 directly collides. The off-gas introduced from the off-gas introduction portion 16 collides with the collision portion 12a. As a result, the liquid (moisture, etc.) in the offgas adheres to the collision part 12a, and the liquid (moisture, etc.) is separated from the offgas.

Only one collision portion 12a is provided. The collision part 12 a is provided at the upper end (including its vicinity) of the gas-liquid separator 10 and is provided at a position above the gas discharge part 16 . The collision part 12a is located directly above the gas discharge part 16 when viewed from the gas flow direction of the gas discharge part 16 (view A in FIG. 1). At least one step portion 20 is provided between the gas discharge portion 16 and the collision portion 12a in the vertical direction. However, the stepped portion 20 may not be provided. The gas discharge part 16 and the collision part 12a are provided on the same side surface 10a of the gas-liquid separator 10 via the stepped part 20 when the stepped part 20 is provided.

The offgas introduction part 14 is tubular, and only one is provided. The offgas introduction part 14 is provided at the upper end of the gas-liquid separator 10 (including its vicinity). The off-gas introduction part 14 is provided on a side surface 10b of the gas-liquid separator 10 opposite (to face) the side surface 10a on which the collision part 12a and the gas discharge part 16 are provided.

The gas discharge part 16 is tubular, and only one is provided. The gas discharge part 16 is provided at the lower end of the separation part 12 (including its vicinity).

The drainage section 18 is provided below the separation section 12 . A partition plate 42 having a vertical hole 42a is provided between the liquid drain section 18 and the separation section 12 . Since the partition plate 42 is provided, the liquid separated by the separation section 12 and flowed from the separation section 12 to the drainage section 18 is prevented from returning to the separation section 12 again. The bottom surface 18a of the liquid draining part 18 is inclined so that the liquid collects at one point (for example, the center) of the bottom surface 18a. The liquid drain section 18 has a valve 18b. When the valve 18b is closed, the liquid separated by the separation section 12 is stored in the liquid drain section 18. When the valve 18b is open, the liquid is discharged from the liquid drain section 18. It is discharged outside the liquid separator 10 . The valve 18b may be provided on the bottom surface 18a of the drainage part 18, or if the drainage part 18 has a drainage pipe 18c connected to the bottom surface 18a, the valve 18b may be provided on the drainage pipe 18c. good.

In the gas-liquid separator 10, the liquid separated by the collision part 12 flows downward by its own weight at a position below the collision part 12a and above the gas discharge part 16, and flows into the gas discharge part 16 through the shortest distance. A canopy (may also be referred to as a canopy) 24 is provided to suppress the movement. The umbrella portion 24 is provided in a later-described gas discharge portion upper portion 12b.

The head portion 24 is configured such that the off-gas introduction portion 14 extends into the separation portion 12 from the side surface 10a (the inner surface of the separation portion 12) on which the collision portion 12a and the gas discharge portion 16 are provided among the side surfaces of the gas-liquid separator 10. It is provided so as to protrude in a substantially horizontal direction toward the side surface 10b on the side where it is provided. The protruding end of the head portion 24 does not reach the side surface 10b on which the off-gas introducing portion 14 is provided, and is located away from the side surface 10b. Umbrella portion 24 has, for example, a flat plate shape. However, in order to secure the rigidity and strength of the head portion 24, a concave portion may be formed in a part thereof, or a rib or the like may be provided.

The umbrella portion 24 is located directly above the gas discharge portion 16 and directly below the collision portion 12a as shown in FIG. 5 in view A of FIG. Further, the width of the head portion 24 in view A of FIG. 1 (length in the horizontal direction in view A) is larger than the diameter of the gas discharge portion 16 (diameter at the inlet).

In the gas-liquid separator 10 , a plurality of grooves 26 extending in the vertical direction are formed in the inner side portion of the separating portion 12 . The groove 26 is formed in at least a portion of the inner surface of the separating portion 12, excluding a portion 12b located above the gas discharge portion 16 (hereinafter referred to as a gas discharge portion upper portion) 12b. The grooves 26 may be provided in the entire side surface portion of the inner surface of the separation portion 12 excluding the gas discharge portion upper portion 12b. Since the groove 26 is provided, the liquid separated by the separation section 12 and adhered to the side surface of the separation section 12 flows downward along the groove 26 to the drainage section 18 by its own weight.

Although the size of each groove 26 is not particularly limited, it is, for example, 0.5 mm wide and 1 mm deep as shown in FIG. If the size is reduced below this size, it becomes difficult to secure the strength of the molding die for molding the groove 26 (ensure manufacturing requirements). Further, if the size is increased beyond this size, the number of grooves 26 is reduced, and the liquid guide effect of the grooves 26 is reduced.

As shown in FIG. 5, among the plurality of grooves 26, the distance between the first groove 26a provided closest to the gas discharge portion 16 and the second groove 26b provided next to the first groove 26a is is smaller than the interval between two grooves 26 adjacent to each other. Although not particularly limited, the interval between the first groove 26a and the second groove 26b is, for example, 4.5 mm, and the interval between the other grooves 26 is, for example, 6.5 mm.

The off-gas introduced into the gas-liquid separator 10 from the gas introduction part 14 is introduced from the gas introduction part 14 into the separation part 12 and collides with the collision part 12 a of the separation part 12 . Therefore, the liquid in the offgas adheres to the collision part 12a, and the liquid is separated from the offgas.
The off-gas from which the liquid has been separated flows through the separation section 12 and into the gas discharge section 16 , and is discharged to the outside of the gas-liquid separator 10 through the gas discharge section 16 .

The liquid separated from the off-gas flows downward under its own weight along the grooves 26 except for the upper part 12b of the gas discharge part, and flows to the liquid discharge part 18 through the holes 42a of the partition plate 42. On the other hand, the liquid separated from the off-gas and flowing downward under its own weight in the upper portion 12b of the gas discharge portion hits the umbrella portion 24 and flows along the upper surface of the umbrella portion 24 as indicated by the arrow in FIG. 24 and flows downward from both outer sides of the umbrella portion 24 . Therefore, the liquid flowing downward through the gas discharge portion upper portion 12 b flows downward avoiding the gas discharge portion 16 by the umbrella portion 24 , passes through the hole 42 a of the partition plate 42 , and flows to the liquid discharge portion 18 .

Also in the gas discharge portion upper portion 12 b , for example, an inverted V-shaped auxiliary groove 28 may be provided that slopes downward and outward from the gas discharge portion 16 above and/or below the umbrella portion 24 . By providing the auxiliary groove 28, the liquid flowing in the upper part 12b of the gas discharge part can flow toward both sides of the gas discharge part 16, and the liquid separated by the separation part 12 can be prevented from flowing into the gas discharge part 16. can be suppressed further.

The liquid that has flowed to the drain portion 18 is stored in the drain portion 18 when the valve 18b is closed, and is discharged from the drain portion 18 to the outside of the gas-liquid separator 10 when the valve 18b is open.

The gas-liquid separator 10 described above is made of resin, and has a four-part structure consisting of an upper member 40, a lower member 41, a partition plate 42 and a strainer 43, as shown in FIG. However, at least one of the upper member 40, the lower member 41, the partition plate 42, and the strainer 43 may be made up of a plurality of parts, thereby forming a part structure of five or more parts.

As shown in FIG. 3 , the upper member 40 is provided with the separation section 12 , the off-gas introduction section 14 and the gas discharge section 16 . A groove 26 and an auxiliary groove 28 are provided on the inner wall surface of the upper member 40 . As shown in FIG. 2, the lower member 41 is arranged below the upper member 40 and fixed to the upper member 40 by welding or the like. The lower member 41 is provided with a drainage portion 18 . The partition plate 42 is sandwiched between the upper member 40 and the lower member 41 to separate the separation section 12 and the drainage section 18 . The strainer 43 is provided with an umbrella portion 24 . The strainer 43 has a frame portion 43a for supporting the umbrella portion 24 in addition to the umbrella portion 24. The strainer 43 is fixed and attached to the seat portion 40a (see FIG. 5) provided on the upper member 40 by the frame portion 43a. It is

Next, the operation and effect of the embodiment of the present invention will be explained.
As shown in FIG. 5, since the umbrella portion 24 is provided, the liquid separated by the collision portion 12a of the separation portion 12 flows downward under its own weight (through the shortest distance) and flows into the gas discharge portion 16. can be suppressed. Therefore, compared to the case where the head portion 24 is not provided, the liquid separated by the separation portion 12 can be suppressed from flowing into the gas discharge portion 16, and the gas-liquid separation performance of the gas-liquid separator 10 can be improved. can be done.

Since the head portion 24 protrudes into the separation portion 12 from the inner surface of the separation portion 12, the head portion 24 can be provided with a simple structure, which is advantageous in terms of cost.

In the gas-liquid separator 10 , a plurality of vertically extending grooves 26 are formed in the side surface portion of the inner surface of the separation section 12 , so the liquid separated by the separation section 12 flows along the grooves 26 . Therefore, compared to the case where the groove 26 is not provided, the liquid adhering to the inner surface of the separation section 12 can be efficiently guided to the liquid discharge section 18 . Therefore, it is possible to prevent the liquid separated by the separation section 12 from re-scattering due to the gas flow and flowing into the gas discharge section 16 .

Since the interval between the first groove 26a and the second groove 26a is smaller than the interval between the other two adjacent grooves 26, the interval between the first groove 26a and the second groove 26b is the other adjacent interval. The first groove 26a can be provided farther from the gas discharge portion 16 than when the distance between the two grooves 26 is the same. Therefore, the liquid flowing along the first grooves 26 a can be flowed away from the gas discharge portion 16 , and the liquid flowing along the first grooves 26 a can be prevented from flowing into the gas discharge portion 16 .

10 Gas-liquid separator 12 Separation part 12a Collision part 12b Gas discharge part upper part 14 Off-gas introduction part 16 Gas discharge part 18 Drainage liquid 18a Bottom surface 18b Valve 18c Drainage pipe 20 Stepped section 24 Head section 26 Groove 26a First groove 26b 2nd groove 28 auxiliary groove 40 upper member 40a seat portion 41 lower member 42 partition plate 42a hole 43 strainer 43a frame portion 100 stack 101 fuel gas source 102 inlet side fuel gas pipe 103 outlet side fuel gas pipe 104 fuel gas circulation pipe 105 Circulation pump 106 Compressor 107 Air cleaner 108 Humidifier 109 Oxidizing gas pipe 110 on the inlet side Oxidizing gas pipe on the outlet side

Claims (1)

A gas-liquid separator for separating a liquid from a fuel cell off-gas, comprising:
a separation unit that separates a liquid from the off-gas;
an offgas introduction section that introduces the offgas into the separation section;
a gas discharge unit for discharging the off-gas, the liquid of which is separated by the separation unit, from the separation unit to the outside of the gas-liquid separator;
a liquid drain section provided below the separation section into which the liquid separated by the separation section flows and is discharged to the outside of the gas-liquid separator;
has
The separation section has a collision section provided at a position above the gas discharge section and at a position opposite to the offgas introduction section, where the offgas introduced from the offgas introduction section directly collides,
A head portion is provided at a position below the collision portion and above the gas discharge portion to prevent the liquid separated by the collision portion from flowing downward under its own weight and flowing into the gas discharge portion,
The width of the umbrella portion is larger than the diameter of the gas discharge portion ,
A partition plate partially having a vertical hole is provided between the drainage unit and the separation unit.
Gas-liquid separator for fuel cells.

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